Nickel-cobalt-manganese complex hydroxide particles and method for producing same, positive electrode active material for nonaqueous electrolyte secondary battery and method for producing same, and nonaqueous electrolyte secondary battery

An object of the present invention is to provide nickel cobalt manganese composite hydroxide particles having a small particle diameter and a uniform particle size distribution, and a method for producing the same. A method for producing a nickel cobalt manganese composite hydroxide by a crystallization reaction is provided. The method includes: a nucleation step of performing nucleation by controlling a pH of an aqueous solution for nucleation including metal compounds containing nickel, cobalt and manganese, and an ammonium ion donor to 12.0 to 14.0 in terms of the pH as measured at a liquid temperature of 25° C. as a standard; and a particle growth step of growing nuclei by controlling a pH of an aqueous solution for particle growth containing nuclei formed in the nucleation step to 10.5 to 12.0 in terms of the pH as measured at a liquid temperature of 25° C. as a standard.